I feel like just killing myself Life is getting unbearable?!

I am 59 my mom is 85.She has been in a nursing home for 2 yrs.I have one sis who works full time.Moms leg got broke and nobody reported any injury.My sis found it.We sent her to the hospital.Her Hemoglobin was 8 she had blood in her bowel,she had severe dehydration,and a raging urinary tract infection.she had surgery Friday with a spinal and got the upper leg repaired.She was in so much pain.We can't send her back to the nursing home to be neglected again.My sis is a work a holic and she can't possibly take her in .I don't work.I have high blood pressure.I lost my daughter 5 yrs ago and my g/grand daughter died at 7 weeks from Sids? not sure yet autopsy not back....my daughter had major surgery on her leg for a congenital defect and her long term care insurance is being can cancelled next month.My son is headed to Afghanistan in the near future.My g/son is a diabetic. I want to bring mom home for her last days.I am so stressed out I don't know what to do.moving her to another nursing home is not the answer they are all alike.She only weighs 98 lbs...I just feel like running my car off a cliff or taking an overdose.How much more can I stand.There are 2 people who I want to kill first.My g/sons step mother and his g/fs father who have refused to pay on my g/granddaughters gravestone.They both are pure evil and I can't begin to tell u what all they have done to hurt my g/son and his g/friend.His mom my daughter died 5 yrs ago and step mom has done everything she can to make his life miserable.My husband is on home dialysis but he takes care of himself so her wont' need me.I have 10 grandchildren whom I love dearly.but I just can't take it anymore.I feel so tired.I feel so hopeless.I feel like my family has a curse like the Kennedy's.Some please tell me what to do.I am at the end of my rope.